Means for preventing current leakage in electric cables.



S` D. SPRONG & VV. E. McCOY.

MEANS Fon PREVENHNG CURRENT LEAKAGE 1N ELECTRIC CABLES.

APPLICATION FILED DEC. I2. \9l6.

Patented May 22; 1917.

UNITED STATES PATENT OFFICE.

sEvEBN n. sPRoNG'aNn WALTER *r1-Macomer N'Ew YORK, N. Y.

.MEANS son rnEvENTINd CURRENT LEA-Kaos IN ELECTRIC CALLES.

Be it known that we, Seven-N D. SvuoNo and lVa'L'rnn E. McCor, citizensof the United States, residing at New York,l iu the county of- NewYorkand State of New York,-

have inventedV a certain .new and useful-Imrovement 1n Means forPreventing Current leakage-in Electric Cables,- of which the'followingis aspecifi'cation.

The invention relates to the prevention of current leakage in electriccables, and -is an embodiment of the principle set forth 1n U. S;Letters PatentiNo. 1,165,140, audll. S. 1LettersPatentNo. 1,105,141,granted to. us

December 21, 1915. The invention consists' lineg/,y'y of Fig. 1'. Fig. 3is a longitudinal 'recesses N which receive-the conductors A section ofan end portion of the joint on the' line 2,2 of Fig.'2. Fig. 4 showsonel of the blocks Lyin perspective. n

Sim'lar letters of reference indicate like parts.4

. A and B are line 'conductors inclosed in the usuallead sheath C, C.Each line inductor.'

comprises an internal metallic con uctorD and an outer insulatingVeoverin In'applying our invention, We procee as followsz'.

The lead VsheathsC, C are eut baektoexpose the 'ends ofntheli'neconductors '.A, B, the inf' sulating coverings E .of which 'are alsore-` moved for a certain distance. The metallicconductors are 'connectedby'any suitable coup1ings,-1is shown'at F. We thenvplace' uponeach'carble similar tubes G, Il, Aeach formed of a plate of fiber orother insulatin material, with a Hat sidefl and a longitudn.

J oppositesaid {iat-side. 'The'twg H aredisposed with their flatsides onthem 'is-placed a nal ga 1 tubes I in contact, an'flu cylindrical tube Ko -fiber or other insulat` lng'material. The leng'tluof the inner tube".ss--than that of tli'e inelosing tl'lbe such'l'; 's orcelain. 'The.outer end-faces M of each' lock are curved t'o lfit the tnbe'K.

On Aopposite sidesv of the'block are concave spe'cination of Lettersraient.'

' above--describedl' Flnto the ends of tube K we insert two' Patented DIa-y'22, 11917.

Appliea'mn mea December 12, 191s. semi m. '1ae,4'o2.

B. On` the .ends of one face of the block are projectionsO-,triangularin cross section.

-When the block is i n place, the projections (l enter ,between theinner tubes G, H, and abut against the' ends of said tubes. ,The oliterside P of each bloclcis-'preferabl' fiat and registers .iviththe endofthe vtube l( shown in'FigJ. Because' the blocks L receive theconductors A, B in their side recesses N, they aid'in keeping saidconductors in properposition. The projections-Oserve asabutmentstopi-event any longitudinal displacement' lof the tubes (i, Hwithin the tube K,"and also retain said tubes in proper relativeposition.

Before the parts are assembled, we place upon one end of the sheath Casleeve Q of similar'metal, which is slid back on said sheath until ,saidarts are assembled, as

Spidfsleeve is then moved forward to cover the -said'parts and tooverlap the ends of the leadA sheath C, Cl 'Itis then united-'to one end'of s'aidsheath,'pref -erably .bya' wiped joint, as shown .at R. Throughthe open end of. the sleeve we introducea lling of insulating material,indicated at S, which permeates 4the interstices within'sleeve Q. 4TheopenJend of the sleeve is4 then closed b .a similar, wiped joint R.

.In'Fig 1, this ii ling' is shown at one end of the tube K It isvomitted-elsewhere in Fig.

1, and also in Fig. 3, for the sakelof cleari ness 1in showing theparts.

Withjthis construction, any leakage eur-V rent4 starting fromonemetallic conductor, as

A., must pass through the iilling S to the gap J 'in tube G, andthencethrough the' joints betweeii -said .tubes G, H'and tube K tothegap in-tube H, and then through the -filling in that tube before it canreach' the metallic cone'uetonB, which is practically 'impos-j sible.'We thus secure effective insulation of. both conductors A., B, andeliminate current leakage f rom one to the other. The dielectricstrengthof v.the material of tubes G, H isto be greater than that of thefilling S.

1'. A n electric` cable,`comprisin'g Van inclosn'lgtube of insulatinmaterial, two jointedV -li ne..con'ductors therein, a filling ofinsulating, material in said inclosing tube andinlner tubes ofinsulating material oi greater dielectric strength than said fillingembeddbd in said filling and r ectively inclosigv .said conductors, eachof vsaid inner tubes havnc side. and the said flat sides being` incontact, and each of said tubes hayi'n a longitudinal gap in its wallopposite its at side. f 'l 2. An electric cable, comprising an inclosingtube of insulating material; two

jointed line conductors therein, a filling of its fiat side, the saidinner-tubes being of less length than said inclosing tube, and blocks ofinsulating material 4disposed in the ends of said inclosing tube andabuttin l against the ends of said inner tubes.

3. An electric cable, -comprising an inelos-l ing tube of insulatingmaterial, two jointed line'conductors therein, a filling of insulat-.conductorse ach of S ,a flat side, and the said fiat sides-bein in attheir-'ends lateral tubes of insulatin material of greater dielectricstrength t, an said filling embedded 5 in said filling and respebtiv'elyinclosing said inner tubes having contact, and each of said'tubeshaving' a ongitudinal side, the sald inner tubes being of les's 'lengthVthan said inclosing'tube, and blocks lSoif 1n- -sulating material disosed in the ends of said inclosingtube an abuttin a. ains't the ends ofsaid'inner tubes, the sai b rejections entering the spaces'betweensaiinner tubes and saldinclosng tube.

In testimony whereof weh'ave aixedour signatures in presence oftwowitnesses."

SEVERN D. SPRONG. e y WALTER EMCCOY. Witnesses:

GERIRUDE T. Poma,

my r. Moslim.

ing material in said inclosing tube, innen;

gap in its wall opposite lts fiat 30 ocks hav- 35

